The present invention relates to a laser machine tool and laser heads for the machining of workpieces by laser ablation.
Laser machine tools for machining workpieces by laser ablation are generally known. The European patent application EP 2 301 706 A2 describes for instance a possible technical design for such an apparatus.
An imaginable configuration and design for such a known laser machine tool for machining workpieces by laser ablation is shown in FIG. 1. The laser head 1 of the displayed machine operates with 5 mechanical axes and allows the positioning of the laser focal point and the direction of the emitted laser beam on the surface of a three-dimensional solid workpieces situated within the machine (not shown). Several machine configurations are imaginable: For instance a workpiece-holder or—as shown in FIG. 1—a laser head which is linear movable in three axis (Cartesian X, Y, Z system). Preferably, allowing a higher accuracy and flexibility, the workpiece-holder or the laser head are in addition able to rotate with high precision on two rotational axes.
There is a growing demand for using the laser machining process on increasingly large workpieces (e.g. for the production of moulds for the manufacturing of dashboards or bumpers of cars and trucks). This made it necessary to design new laser machine tools of large dimensions.
Today there is also a demand in the aviation industry for turbine drilling applications with engraving of the port exhaust to optimize the vortices. Those applications require first the drilling under a drilling laser head and the subsequent laser engraving under a suitable laser engraving head. Due to very different required machine characteristics, it is not possible to accomplish both machining steps with the same laser head. So far, the laser drilling and the following laser engraving have always been conducted on separate laser machines tools by moving the workpiece first under the drilling laser head and subsequently to the next machine under its laser engraving head.
This practice is possible for smaller workpieces, which can be easily moved for instance pre-mounted on clamping devices from machine to machine. For bigger, bulky and heavier workpieces however, this practice gets laborious and might in addition negatively affect the manufacturing accuracy due to a the bigger risks of misalignment in view of the size of the workpieces to be machined.
Apart of this, two laser machine tools are necessary for the manufacturing, increasing therewith the necessary investments for the production line and, of course, the manufacturing costs.
The present invention aims therefore to solve this problem.